International Journal of Trend in Research and Development, Volume 3(3), ISSN: 2394-9333
www.ijtrd.com
Development of Mechanism for Recovery of Lost Energy
of Suspension System: Regenerative Shock Absorbers
1
Ajinkya Pagar and 2S Y Sonaye,
1
Student, 2Professor,
1,2
Department of Mechanical Engineering, Smt Kashibai Navale College of Engineering, Pune, India
Abstract – We know that automobiles are inefficient, wasting
over 74% of energy which is stored in fuel as a heat. It includes
various losses occurring in different parts like vibration of
engine, losses while braking, losses of drag, etc. Thus only
26% of the available fuel energy is used to drive the vehicle
that is to overcome the resistance from road friction. One
important loss is the dissipation of vibration energy by shock
absorbers in the vehicle suspension under the excitation of road
irregularity and vehicle acceleration or deceleration. In this
paper, some of the results and ways which show the
effectiveness of efficiently transforming that energy into
electrical power by using optimally designed regenerative
shock absorbers are discussed. In turn, the electrical power can
be used to recharge batteries or other efficient energy storage
device rather than be dissipated. The study suggests that a
significant amount of the vertical motion energy can be
recovered and utilized.
Keywords - Regenerative Shock Absorber, Energy recovery,
Efficiency, Power generating Shock Absorber
damper to improve the suspension performance or to power
vehicle electronics to increase vehicle fuel efficiency [1].
II. SHOCK ABSORBER
A shock absorber is a mechanical device designed to smooth
out or damp shock impulse, and convert kinetic energy to
another form of energy (usually thermal energy, which can be
easily dissipated). A shock absorber is a device which
transforms mechanical energy into thermal energy [2].
A.
Only 10-20% the fuel energy is used for vehicle mobility,
wasting over 74% of energy stored in fuel as a heat Major
energy losses are engine losses (62.5%), idle and standby
(17.2%), braking losses (5.8%), rolling resistance (4.2%) &
drive line losses (5.2%), accessory usage (2.5%), and
aerodynamic drag (2.6%)[2]. One of the important losses is the
energy dissipation in suspension vibration concluded that the
dissipated energy by suspension dampers is related with road
roughness, vehicle speed, suspension stiff and damping
coefficient.
I. INTRODUCTION
B.
In the past decade, regenerative braking systems have become
increasingly popular, recovering energy that would otherwise
be lost through braking. However, another energy recovery
mechanism that is still in the research stages is regenerative
suspension systems. This technology has the ability to
continuously recover a vehicle's vibration less energy
dissipation that occurs due to road irregularities, vehicle
acceleration, and braking, and use the energy to reduce fuel
consumption. Consumption; however, only 10%–20% fuel
energy in the vehicles is utilized for driving to overcome
resistance from road friction and air drag [2]. In addition to
thermal efficiency and braking energy, one important loss is
kinetic energy dissipated by shock absorbers. The function of
vehicle suspension system is to support the weight of vehicle
body, to isolate the vehicle chassis from road disturbances, and
to enable the wheels to hold the road surface. Two chief
elements in suspension are spring and damper. Conventionally,
damper is designed to dissipate vibration energy into heat to
attenuate the vibration which is transmitted from road
excitation. However, the dissipated heat is from fuel or
electrical power.
Green manufacturing, also called environmentally conscious
manufacturing, is one of the most popular topics nowadays.
The future of green manufacturing technology is foreseeable,
especially on vehicle industry. Since the suspension is an
important source of energy dissipation, it is feasible to harvest
its vibration energy and convert into regenerative energy to
improve the vehicle fuel efficiency. Therefore, so called
regenerative suspensions arise as the times require. Instead of
dissipating the vibration energy into heat wastes, the damper in
regenerative suspension will transform the kinetic energy into
electricity or other potential energy and store it for late use.
The stored energy can be used to tune the damping force of the
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Energy Dissipation Of Vehicle Suspension
Energy Harvest From Vehicle Suspension
The harvested energy in the regeneration process is enough to
meet the energy requirement in consumption process for
electromagnetic active suspension, which means the
suspension is self-powered.
III. REGENERATIVE SHOCK ABSORBERS
Figure 1: Three-dimensional model and photo of the shock
absorber prototype [3].
The Regenerative Shock Absorbers that is Power Generating
Shock Absorbers (PGSA) converts this kinetic energy into
electricity instead of heat through a Linear Motion
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International Journal of Trend in Research and Development, Volume 3(3), ISSN: 2394-9333
www.ijtrd.com
Electromagnetic System (LMES). The LMES uses a dense
permanent magnet stack embedded in the main piston, a
switchable series of stator coil windings, a rectifier, and an
electronic control system to manage the varying electrical
output and dampening load. The bottom shaft of the PGSA
mounts to the moving suspension member and forces the
magnet stack to reciprocate within the annular array of stator
windings, producing alternating current electricity. That
electricity is then converted into direct current through a fullwave rectifier and stored in the vehicle’s batteries. The
electricity generated by each PGSA can then be combined with
electricity from other power generation systems and stored in
the vehicle’s batteries to increase battery life. In non-electric
vehicles the electricity can be used to power accessories such
as air conditioning. Several different systems have been
developed recently, though they are still in stages of
development and not installed on production vehicles [2].
A. Description
The mechatronic system we have chosen to model is PowerGenerating Shock Absorber (PGSA) acting on an automotive
chassis. The shock absorber will be used in conjunction with a
spring to simulate one of the four suspension system of an
automobile. When designing an automotive suspension system
the key is to balance the ride of the automobile. More
specifically, the suspension is meant to absorb the effects of an
uneven driving surface and tilt/sway of the car. However,
excess energy loss occurs due to resistance in the damper fluid
and compression of the spring. The PGSA converts kinetic
energy into electricity through the use of a Linear Motion
Electromagnetic System (LMES). The absorber consists of a
damper with permanent magnet stack that slide in and out of
stator windings connected to two sliding blocks inside the
damper casing.
some disadvantages. One, the complex pipeline system has
considerable weight and need more installation room. Two,
hose leaks and ruptures may disable the whole system. Three,
the responding bandwidth of hydraulic / pneumatic systems is
narrow, which confines the suspension performance. Four, the
reuse of the regenerated hydraulic / pneumatic energy are
limited, especially when the automotive industry is toward
commercializing hybrid electric vehicles and full electric
vehicles. Hence, the researches on hydraulic / pneumatic
regenerative suspension are relative rare.
B. Electromagnetic Regenerative Suspensions
On the contrary, electromagnetic regenerative suspension
transforms the shock energy into electric energy that is more
convenient to store and reuse, and has high performance,
increased efficiency, less space requirements, and so on. In
recent years, electromagnetic suspension (EMS) system has
drawn worldwide attention. Permanent magnets motor is
favoured in EMS to provide active force in actuator mode or
damping force in generator mode. The damping force can be
simply changed by tuning the shunt resistances.
Figure 3: Schematic of the regenerative suspension system [3].
V. REQUIREMENTS FOR CONTRUCTION
a.
b.
c.
d.
Figure 2: Example of Power-Generating Shock Absorber [2].
IV. CONFIGURATION OF REGENEREATIVE
SUSPENSION
According to the working principle, the regenerative
suspension can be divided into two types: mechanical and
electromagnetic regenerative suspension [1].
A. Mechanical Regenerative Suspensions
The mechanical regenerative suspension is reformed from the
traditional hydraulic/ pneumatic suspension. It absorbs the
kinetic energy of suspension and converts into potential
hydraulic / pneumatic energy to be stored in accumulator.
However, these hydraulic / pneumatic systems characterize
IJTRD | May-Jun 2016
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Suspension systems which is a main part of assembly.
An electric motor which converts the magnetic effect into
electricity.
Four wheel drive on which suspension system is
assembled.
Wiring of whole system through which electricity is being
generated [2].
VI. CONTRUCTION
The system uses a dense permanent magnet stack embedded in
the main piston, a switchable series of stator coil windings, a
rectifier, and an electronic control system to manage the
varying electrical output and dampening load. The bottom shaft
of the regenerative shock absorber mounts to the moving
suspension member and forces the magnet stack to reciprocate
within the annular array of stator windings, producing
alternating current electricity [2].
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International Journal of Trend in Research and Development, Volume 3(3), ISSN: 2394-9333
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VII. WORKING
The Power-Generating Shock Absorber (PGSA) converts this
kinetic energy into electricity instead of heat through the use of
a Linear Motion Electromagnetic System. Shock absorbers are
installed between chassis and wheels to suppress the vibration,
mainly induced by road roughness, to ensure ride comfort and
road handling. Conventional rotational regenerative shock
absorbers translate the suspension oscillatory vibration into
bidirectional rotation, using a mechanism like ball screw or
rack pinion gears. Figure 4 shows one such an implementation,
where the rotary motion is changed by 90 degree with a pair of
bevel gears for retrofit. And electricity generated in this
mechanism. That electricity is then converted into direct
current through a full wave rectifier and stored in the vehicle’s
batteries [2].
introduction into the automotive world is the next logical step.
This technology can be applied to any type of vehicle that
employs movable suspension technology and uses electricity in
some form as its fuel. To validate the given analysis and
demonstrate energy harvesting from the shock absorbers, we
carried out road tests using a Chevrolet Surburban SUV (2002
model). The experiment setup is shown in Figure 5. [3]
The displacement of the rear shock absorber was recorded by a
laser displacement sensor from Micro-Epsilon with a sampling
rate of 1000 points/s. The output voltage is recorded with a
digital signal analyzer HP 35670A. The road tests were
conducted on the campus road of Stony Brook University,
Stony Brook, NY, at different speeds, including 48 and 32
km/h. The recorded voltages on an external electrical load of
30 Ω generated from the energy-harvesting shock absorber at
these two vehicle speeds are recorded. It is shown that the peak
voltages were over 40 V. Correspondingly, the peak powers are
67.5–58.2W. The average power values are 4.8 and 3.3W,
respectively, at 48 and 32 km/h (30 and 20 mi/h), or 19.2 and
13.2 W can be harvested on four shock absorbers at 48 and 32
km/h. The results from the road tests are encouraging,
although the harvesting efficiency in road tests cannot be
drawn from these values since the suspension vibration highly
depends on the road conditions [2].
Figure 4: Traditional design of a rack-pinion based power
generating shock absorber [2].
The suspension system consist two types of cylinder. One have
larger diameter and another have smaller diameter. When
suspension is applied, the smaller diameter cylinder moves into
the larger diameter cylinder which produces magnetic field due
to repetition of movement of cylinders over coils. Then the
electric motor converts the magnetic effect into electricity
which is to be stored in battery.
VIII. ADVANTAGES
a.
b.
c.
d.
e.
Shock absorbers have a great for performance, handling
and stability. 
They are best choice for work and severe use vehicles.
High pressure gas mono tube design- 360psi to prevent
aeration and shock fade. These have a lightervalving than
the heavy duty units.
Low pressure gas twin tube design- These units are good
for average, everyday driving and a
very
goodreplacement for OE units.
The “electricity generating suspension system” has a much
higher energy yield than other known invention.
Figure 5: Setup of Road Test. (Top) Vehicle, (Bottom Left)
Instruments, (Bottom Right) Mounting of Sensors and Shock
Absorber [3].
IX. DISADVANTAGES
a.
b.
c.
d.
e.
f.
g.
Complexity
Problem occurred in collecting materials.
Time consuming.
Found some drawbacks of suspension system like rubbing
in (LWV) light weight vehicles.
In case of Induction Brakes, whole system can undergo
failure because of electric motor.
As whole system consist electric wiring so this may occur
short circuit of system.
This system consist a speed limit up to 35 km/h [2].
X. APPLICATION
Linear Motion Electromagnetic System (LMES) technology is
already finding its place in ocean power generating systems. Its
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XI. REMARKS
A. Conflict
The primary purpose of improving suspension performance is
to better ride comfort and handling stability, such as active
suspension, semi-active suspension. Active suspension owns
the best vibration control performance, but must consume lots
of energy, while the actuator just works as passive or semiactive damper in regeneration process, whose control
performance is not excellent as that of active state. So as to
saving energy, despite some strategies may be established to
reach the balance between regenerated and consumed energies,
we have to scarify vibration control performance evidently.
Thereby, there is conflict between regeneration and vibration
control [1].
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International Journal of Trend in Research and Development, Volume 3(3), ISSN: 2394-9333
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B. Efficiency
For regenerative suspension, how to enhance the efficiency of
harvesting energy is very important. For absence of speed
increaser, the direct-drive motor has a low energy recovering
efficiency. However, as to ball screw and rack-pinion damper,
speed increaser leads to more inertia loss which decreases the
regeneration efficiency and suspension performance. In
comparison, the hydraulic transmission regenerative damper
shows obvious advantage in term of regeneration efficiency
since it is expedient to equip speed increaser and there is no
inertia loss resulting from alternating the rotation direction
frequently [1].
C. Reliability
Reliability is a key factor for engineering application. Directdrive motor has a high reliability for itself, but any faults in
circuit will result in disappearance of damping force, which
doesn’t accord with the fail-safe principle. For ball screw and
rack-pinion harvester, bump excitations or alternating rotation
directions frequently will result in damage of harvester.
Hydraulic transmission and self-powered MR damper have a
high reliability [1].
for the guidance for my paper. So I could complete my paper
on “Development of Mechanism for Recovery of Lost Energy
of Suspension System: Regenerative Shock Absorbers”.
I also thanks respected authors whose papers I have
referred which are given if references Zhang Jin-qiu, Peng
Zhi-zhao, Zhang Lei, Zhang Yu, Meghraj P.Arekar, Swapnil
Shahade, Zhongjie Li, Lei Zuo, George Luhrs, Liangjun Lin,
and Yi-xian Qin, Vikram Kedambadi Vasu, Susheel J, Peng Li,
Lei Zuo, Jianbo Lu Li Xu, Mr. Swapnil Kamthe, Mr. Rahul
Kadam, Mr. Aniket Dhore, Mr. Shivkumar Falmari, Prof.
Subhash Ghadve, Prof. Mukesh Chaudhari, Mr. V.V.Borole,
Prof. K.K.Chaudhari for their valuable research work and their
journal paper which has helped me a lot during the study.
I also express my deep sense of gratitude to all those
who directly or indirectly helped me in completing this paper.
References
[1]
[2]
[3]
[4]
[5]
[6]
Figure 6: Simple Illustration of both Shock Absorbers [8]
CONCLUSION
Unlike conventional shock absorbers, regenerative shock
absorbers preserve the energy and it can be utilized further.
This is the main difference between them. It can be simply
understandable by figure 6. Conventionally, the vibration
energy of vehicle suspension is dissipated as heat by shock
absorber, which wastes a considerable number of resources.
Regenerative suspensions bring hope for recycling the wasted
energy. Regenerative suspensions, especially electromagnetic
suspension, and their properties are reviewed in this paper.
With improvement of technology, regenerative suspension may
become one of promising trends of vehicle industry. As the
mechanism is saving energy, it ultimately increases efficiency
of vehicle. It can be called as a vista of green technology.
[7]
[8]
Zhang Jin-qiu, Peng Zhi-zhao, Zhang Lei, Zhang Yu,
“A Review on Energy-Regenerative Suspension
Systems for Vehicles” Proceedings of the World
Congress on Engineering 2013 Vol III, WCE 2013, July
3 - 5, 2013, London, U.K.
Meghraj P.Arekar, Swapnil Shahade, "Power
Generating Shock Absorber", International Journal of
Innovative Research in Science, Engineering and
Technology, Volume 4, Special Issue 3, March 2015
Zhongjie Li, Lei Zuo, George Luhrs, Liangjun Lin, and
Yi-xian Qin, "Electromagnetic Energy-Harvesting
Shock Absorbers: Design, Modelling, and Road Tests",
IEEE Transactions on Vehicular Technology, Vol. 62,
No. 3, March 2013
Vikram Kedambadi Vasu, Susheel J, Regenerative
Magnetic Shock Absorbers
Peng Li, Lei Zuo, Jianbo Lu Li Xu, "Electromagnetic
Regenerative Suspension System for Ground Vehicle",
2014 IEEE International Conference on Systems, Man,
and Cybernetics, October 5-8, 2014, San Diego, CA,
USA
Mr. Swapnil Kamthe, Mr. Rahul Kadam, Mr. Aniket
Dhore, Mr. Shivkumar Falmari, Prof. Subhash Ghadve,
Prof. Mukesh Chaudhari, "Developement of Mechanism
for Recovery of Energy of Suspension System",
International Journal of Pure and Applied Research in
Engineering and Technology, 2014; Volume 2 (9): 169178
Mr. V.V.Borole, Prof. K.K.Chaudhari, "A Review on
Electromagnetic Shock Absorber", IORD Journal of
Science & Technology, Volume 2, Issue 3 (MAR-APR
2015)
https://www.google.co.in/search?q=regenerative+shock
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Acknowledgement
I wish to express my sincere thanks and gratitude to
Prof. S. Y. Sonaye for his enthusiastic and valuable guidance.
In spite of his busy schedule, he offered me his valuable time
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